This is the successor to the famous Bob Parker FBT/LOPT kit and companion to the Blue ESR meter kit. This ring tester is in kit form and is an inexpensive and effective way to test any high Q inductive component. It is especially useful for doing a quick check on flyback transformers, line output transformers and other high frequency inductive components like deflection yoke windings and SMPS transformers. This is an indispensable piece of test equipment for a system designer or product technician!. See manual for more details, quality test leads with banana jacks and alligator clips included, see online review by Jestine Yong: http://www.electronicrepairguide.com/blue-ring-tester.htmlView Spec Sheet